scanner: Add a CheckTask for checking if tracks still exist

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

scanner/task.py

@@ -61,3 +61,18 @@ class DirectoryTask(Task):
                 res.append(DirectoryTask(self.library, f))
         res.append(CommitTask())
         return res
+
+
+class CheckTask(Task):
+    def __init__(self, tracks):
+        Task.__init__(self)
+        self.tracks = tracks
+
+    def run_task(self):
+        need_commit = False
+        for track in self.tracks:
+            if not track.path.exists():
+                db.track.Table.delete(track)
+                need_commit = True
+        if need_commit:
+            db.commit()

scanner/test_task.py

@@ -107,3 +107,26 @@ class TestScannerDirectoryTask(unittest.TestCase):
         self.assertEqual(len(file_tasks), 13)
         self.assertEqual(len(dir_tasks), 1)
         self.assertEqual(len(commit_task), 1)
+
+
+class TestScannerCheckTask(unittest.TestCase):
+    def setUp(self):
+        db.reset()
+
+    def test_scanner_check_task(self):
+        lib = db.library.Table.find(test_tracks)
+        for i in [ 1, 2, 3 ]:
+            db.make_fake_track(i, i, f"Test Track {i}", f"{lib.path}/{i}.ogg", lib.path)
+        track = db.make_fake_track(4, 4, "data/Test Album/04 - Test (Disc Two).ogg", lib.path)
+
+        tracks = [ db.track.Table.get(i) for i in [ 1, 2, 3, 4 ] ]
+        ct = task.CheckTask(tracks)
+
+        self.assertIsInstance(ct, task.Task)
+        self.assertEqual(ct.tracks, tracks)
+
+        self.assertIsNone(ct.run_task())
+        self.assertIsNone(db.track.Table.get(1))
+        self.assertIsNone(db.track.Table.get(2))
+        self.assertIsNone(db.track.Table.get(3))
+        self.assertEqual(db.track.Table.get(4), track)